GEIS, A.A.*; WIBBELS, T.; GARDUNO-D., M. ; MARQUEZ-M., R.; BURCHFIELD, P.; SCHROEDER, B.; University of Alabama at Birmingham; University of Alabama at Birmingham; SEMARNAT, Mexico City; Instituto Nacional de la Pesca, Mexico; Gladys Porter Zoo, Brownsville, TX; National Marine Fisheries Service, Silver Springs, MD: Evaluation of Kemp�s ridley hatchling sex ratios within egg corral and in situ nests at the primary nesting beach

The Kemp�s ridley sea turtle, Lepidochelys kempi, is the most endangered sea turtle in the world today. Like all species of sea turtles, the Kemp�s ridley possesses temperature-dependent sex determination (TSD). Since TSD can produce such highly biased sex ratios, it is of ecological and conservational interest to monitor the sex ratios produced in the Kemp�s ridley conservation program. During the 2001 and 2002 nesting seasons, nest incubation temperatures were monitored within the egg corrals (i.e., egg hatcheries) at the primary Kemp�s ridley nesting beach located near Rancho Nuevo, Mexico. Additionally, incubation temperatures were monitored in a subset of nests that remained in situ on the natural nesting beach. Sex ratios were predicted based on the average incubation temperature during the middle third of incubation. Some variation was detected between egg corral and in situ nests. However, in general, incubation temperatures were relatively warm in the majority of nests in the egg corrals and on the natural nesting beach, suggesting the production of female biases during the 2001 and 2002 nesting seasons. These data are consistent with those from three previous years (1998-2000), suggesting the production of female biases during the more recent years of this conservation program.